TAMRON 20-40mm F/2.8 DI III VXD (E-MOUNT): Tamron’s new wide-angle zoom lens is compact, lightweight and moisture-resistant and delivers excellent performance plus near silent operation for vlogging and video recording using Sony full-frame cameras. Versatility and optical performance lift this optic to Editors Choice status.
Only 86.5 mm long and weighing just 365 grams, the Tamron 20-40mm f/2.8 Di III VXD is a surprisingly versatile lens. Its wide angle coverage with minimal distortion makes it a ‘dream lens’ for real estate photographers, while it’s also a good size for family snapshots and street photography, yet delivers high enough resolution to be used for landscape and architectural photography.
Build quality is up to Tamron’s high standards and, although the barrels appear to be made mostly of composite polycarbonate, they are on a sturdy metal mount. A petal-shaped hood is included, in addition to the standard front and end caps. The optical design of this lens is quite complex, comprising 12 elements in 11 groups and including four LD (Low Dispersion), two GM (Glass Moulded aspherical) plus one Hybrid aspherical elements. Tamron’s proprietary BBAR (Broad-Band Anti-Reflection) coating has been applied to suppress internal reflections and the front surface of the lens is fluorine-coated for easy cleaning. Nine diaphragm blades produce a circular aperture for attractive bokeh and 18-pointed sunstars when the lens is stopped down.
Designed for Sony’s full-frame cameras, this lens is compatible with Sony-specific functions like Eye AF, Fast-Hybrid AF and in-camera lens corrections for vignetting, chromatic aberration and distortion. It also supports Direct Manual Focus (DMF) in AF mode and is compatible with the dedicated Tamron Lens Utility software that enables users to customise focusing ring settings and install firmware updates when they are released.
Imatest testing showed the lens to be a very good performer and up with the best lenses we have reviewed so far. The best measured performance in the centre of the frame was at the 24mm focal length with an aperture of f3.5, although the resolution for JPEG files exceeded expectations for the 24-megapixel camera we used for our tests across the entire focal length range, most extensively with the shorter focal lengths at frequently-used aperture settings. Resolution was significantly higher for ARW.RAW files.
In-camera corrections in Sony full-frame cameras eliminate relatively minor issues with vignetting, rectilinear distortion and chromatic aberration and they are also easily corrected when raw files are converted into editable formats. Backlighting was handled well, although some small flare artefacts were produced when a light source was within the frame at the 40mm focal length. Sunstars at f/22 were sharp and well-defined.
1. Tamron’s 20-40mm f2.8 Di III VXD lens is likely to delight prospective buyers, whether they purchase it for a specific purpose like real estate photography, or just for general use. Its winning combination of size, performance and price will be hard to beat.
2. Autofocusing is fast and accurate as well as near-silent thanks to VXD (Voice-coil eXtreme-torque Drive) linear voice-coil motors. Tamron claims they provide positional accuracy down to 0.005 mm, which we found to be credible.
3. The near silent operation is ideal for all kinds of video recording, but especially for vlogging, where the small size and light weight of the lens make it ideal for use with gimbals.
4. Close-up shooting is surprisingly good for a wide-angle zoom lens, with a minimum focus of 17 cm with the 20mm focal length and 29 cm at 40mm. A reproduction ratio of 1:5.1 is possible with the 400mm focal length. Bokeh quality is smooth and attractive.
5. Overall handling is comfortable, with both zoom and focusing rings turning smoothly and making quick adjustments easy. The inner barrel extends a little without changing its orientation when you zoom from 40mm to 20mm.
6. The lens is compatible with Sony-specific functions like Eye AF, Fast-Hybrid AF and in-camera lens corrections for vignetting, chromatic aberration and distortion. It also supports Direct Manual Focus (DMF) in AF mode.
7. Moisture-resistant construction plus a fluorine coating on the front element to resist water, grit and grease enable it to be used for hassle-free location shooting.
8. This lens can accept the same 67 mm diameter filters as eight other Tamron lenses, ranging from the 20mm, 24mm and 35mm f/2.8 primes through to the 17-28mm, 28-75mm f/2.8 and 70-180mm zooms, 28-200mm f/2.8-5.6 zoom, 70-30mm f/4.5-6.3 zoom and 50-400mm f/4.5-6.3 Di III VC VXD zoom lens.
– Margaret Brown
For an extended review including benchtest charts, click here.